Subject: Basic Sciences

National Science Day is commemorated on Feb 28 every year to commemorate the bird anniversary of Sir CV Raman.

National Science Day

• In 1986, the Government of India, under then PM Rajiv Gandhi, designated February 28 as National Science Day to commemorate the announcement of the discovery of the “Raman Effect”.
• The Raman Effect was the discovery which won physicist Sir CV Raman his Nobel Prize in 1930.

Who was CV Raman?

• Raman conducted his Nobel-prize-winning research at IACS, Calcutta.
• While he was educated entirely in India, Raman travelled to London for the first time in 1921, where his reputation in the study of optics and acoustics was known to physicists such as JJ Thomson and Lord Rutherford.
• The Raman Effect won scientist Sir CV Raman the Nobel Prize for physics in 1930.
• It was also designated as an International Historic Chemical Landmark jointly by the American Chemical Society (ACS) and the Indian Association for the Cultivation of Science (IACS).
• His speciality was the study of vibrations and sounds of stringed instruments such as the Indian veena and tambura, and Indian percussion instruments such as the tabla and mridangam.

The Raman Effect

• In 1928, Raman discovered that when a stream of light passes through a liquid, a fraction of the light scattered by the liquid is of a different colour.
• While Raman was returning from London in a 15-day voyage, he started thinking about the colour of the deep blue Mediterranean.
• He wasn’t convinced by the explanation that the colour of the sea was blue due to the reflection of the sky.
• As the ship docked in Bombay, he sent a letter to the editor of the journal Nature, in which he penned down his thoughts on this.
• Subsequently, Raman was able to show that the blue colour of the water was due to the scattering of the sunlight by water molecules.
• By this time he was obsessed with the phenomenon of light scattering.

Observing the effect

• The Raman Effect is when the change in the energy of the light is affected by the vibrations of the molecule or material under observation, leading to a change in its wavelength.
• Significantly, it notes that the Raman effect is “very weak” — this is because when the object in question is small (smaller than a few nanometres), the light will pass through it undisturbed.
• But a few times in a billion, light waves may interact with the particle. This could also explain why it was not discovered before.
• In general, when light interacts with an object, it can either be reflected, refracted or transmitted.
• One of the things that scientists look at when light is scattered is if the particle it interacts with is able to change its energy.

Real-life applications

• Raman spectroscopy is used in many varied fields – in fact, any application where non-destructive, microscopic, chemical analysis and imaging is required.
• Whether the goal is qualitative or quantitative data, Raman analysis can provide key information easily and quickly.
• It can be used to rapidly characterize the chemical composition and structure of a sample, whether solid, liquid, gas, gel, slurry or powder.

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Central idea: The article discusses recent research on the idea that neutrinos might be their own antiparticles, a concept that has been debated in the scientific community for many years.

What are neutrinos?

• Neutrinos are fundamental particles that are similar to electrons but have no electric charge.
• They are one of the most abundant particles in the universe, but they are also one of the most difficult to detect because they interact only very weakly with matter.
• Neutrinos are created in a variety of natural processes, including nuclear reactions in stars, radioactive decay, and cosmic ray interactions.
• They are also produced in particle accelerators and nuclear reactors.

Its types

• Neutrinos come in three different types or “flavors”:

1. Electron neutrinos
2. Muon neutrinos, and
3. Tau neutrinos

• Each flavor of neutrino is associated with a different charged lepton (electron, muon, or tau).

Why study neutrinos?

• Because they are electrically neutral and interact only weakly with matter, neutrinos can pass through enormous amounts of material without being stopped or deflected.
• This property makes them useful for studying astrophysical phenomena such as supernovae and the sun’s interior, as well as for exploring the fundamental nature of matter.

Neutrinos as their own antiparticles

• Particle physics explains that particles and their antiparticles have opposite properties, and they can annihilate each other when they meet.
• Neutrinos are fundamental particles that are difficult to detect as they have no electric charge and interact only weakly with matter.
• The idea that neutrinos could be their own antiparticles is supported by the fact that they are electrically neutral, and they could interact with themselves in a process called neutrinoless double beta decay.

Substantiation of this

• The Majorana Demonstrator experiment is designed to detect neutrinoless double beta decay.
• The experiment has reported some promising results that suggest that neutrinos could indeed be their own antiparticles.

Significance of this theory

• If confirmed, the idea that neutrinos are their own antiparticles could have important implications for our understanding of the fundamental nature of matter and the universe as a whole.
• More research will be needed before any definitive conclusions can be drawn, but the results of the Majorana Demonstrator experiment provide some promising evidence for the idea that neutrinos are their own antiparticles.

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Central idea: A rare and unique meteorite, known as the Diyodar meteorite, was discovered in Banaskantha, Gujarat in December 2022. It is significant because it is the first aubrite to be found in India in 170 years.

What are Aubrites?

• Aubrites are a type of meteorite that are believed to have formed on a different planet in the early solar system.
• They are known for their unusual mineralogy and composition and are believed to have originated from a differentiated parent body, such as an asteroid or a planetesimal.
• They are primarily composed of a mineral called enstatite, which is a magnesium-rich silicate. They also contain other minerals such as nickel-iron, troilite, and chromite.
• Aubrites are relatively rare, comprising only about 0.1% of all known meteorites.
• They are believed to have formed under highly reducing conditions, with very little oxygen present.

Meteorite found in Diyodar, Gujarat

• The Diyodar meteorite is thought to be around 4.5 billion years old, and it is believed to have originated from the asteroid belt between Mars and Jupiter.
• Its discovery provides scientists with an opportunity to study the composition and structure of these unique meteorites.
• This, in turn, can help researchers to better understand the early solar system and the processes that led to the formation of planets.

Its composition

• Around 90% of the meteorite was composed of orthopyroxene.
• Pyroxenes are silicates consisting of single chains of silica tetrahedra (SiO 4); orthopyroxenes are pyroxenes with a certain structure.
• Pyroxenes such as diopside and jadeite have been used as gems. Spodumene was historically used as lithium ore.
• Rocks with pyroxene have also been used to make a crushed stone that is used in construction.

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Scientists have discovered a new type of quasicrystal, one with 12-fold symmetry, in the Sand Hills of north central Nebraska, USA.

What is a Quasicrystal?

• Quasicrystal is essentially a crystal-like substance.
• However, unlike a crystal, in which atoms are arranged in a repeating pattern, a quasicrystal consists of atoms that are arranged in a pattern that doesn’t repeat itself regularly.
• For the longest time, physicists believed every crystalline arrangement of atoms must have a pattern that repeats itself perfectly over and over again.
• However, this changed in 1982, when material scientist Dan Shechtman discovered crystal structures that are mathematically regular, but that do not repeat themselves.

How are they formed?

• Electrical discharge triggered quasicrystal formation in the recent finding.
• It’s also the first time that researchers have found a quasicrystal somewhere other than meteorites or the debris from nuclear blasts.

Applications of quasicrystals

• There is no major commercial applications yet exploit properties of the quasicrystalline state directly.
• Quasicrystals form in compounds noted for their high strength and light weight, suggesting potential applications in aerospace and other industries.
• They can be used in surgical instruments, LED lights and non-stick frying pans.

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Agasthyarkoodam was once home to a forgotten and long-lost 19th-century observatory established by Scottish meteorologist John Allan Broun.

Agasthyarkoodam Observatory

• The Agasthyarkoodam Observatory is an astronomical research observatory located in the state of Kerala.
• The observatory is situated at an altitude of 1600 meters above sea level and is owned and operated by the Indian Institute of Astrophysics (IIA).
• The observatory is equipped with a 1-meter optical telescope and various other instruments for studying the night sky.
• The observatory is used for research and educational purposes and is open to the public for viewing night-sky objects.

Why in news?

• Agasthyarkoodam in the Western Ghats once housed a magnetic observatory that was established by Scottish meteorologist John Allan Broun.
• Broun used it to record magnetic and meteorological observations in tandem with the Thiruvananthapuram astronomical observatory.
• Broun’s astronomical research in India began after he was invited by the ruler of the erstwhile Travancore Uthram Tirunal Marthanda Varma to helm the Thiruvananthapuram observatory following the death of its first director John Caldecott in 1849.
• The observatory started recording observations in July 1855.
• However, it was closed in 1881 by the then Madras Governor Sir William Denison.

What are magnetic observatories?

• Magnetic observatories continuously measure and record Earth’s magnetic field at a number of locations.
• In an observatory of this sort, magnetized needles with reflecting mirrors are suspended by quartz fibres.
• Light beams reflected from the mirrors are imaged on a photographic negative mounted on a rotating drum.
• Variations in the field cause corresponding deflections on the negative.
• Their magnetograms are photographed on microfilm and submitted to world data centres, where they are available for scientific or practical use.

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Google has finally decided to answer the challenge and threat posed by Microsoft-backed OpenAI and its AI chatbot- ChatGPT.

What is Bard, when can I access it?

• Google’s Bard is functioned on LaMDA, the firm’s Language Model for Dialogue Applications system, and has been in development for several years.
• It is what Sunder Pichai termed an “experimental conversational AI service”.
• Google will be opening it up to trusted testers ahead of making it more widely available to the public in the coming weeks.
• It is not yet publicly available.

What is Bard based on?

• Bard is built on Transformer technology—which is also the backbone of ChatGPT and other AI bots.
• Transformer technology was pioneered by Google and made open-source in 2017.
• Transformer technology is a neural network architecture, which is capable of making predictions based on inputs and is primarily used in natural language processing and computer vision technology.
• Previously, a Google engineer claimed LaMDA was a ‘sentient’ being with consciousness.

How does it work?

• Bard draws on information from the web to provide fresh, high-quality responses.
• In short, it will give in-depth, conversational and essay-style answers just like ChatGPT does right now.
• It requires significantly less computing power, enabling us to scale to more users, allowing for more feedback.

What about its computing power?

• Remember running these models also requires significant computing power.
• For instance, ChatGPT is powered by Microsoft’s Azure Cloud services.
• This also explains why the service often runs into errors at times, because too many people are accessing it.

Key difference between ChatGPT and Google’s Bard

• It appears that to take on ChatGPT, Google has an ace up its sleeve: the ability to draw information from the Internet.
• Bard draws on information from the web to provide fresh, high-quality responses.
• ChatGPT has impressed with its ability to respond to complex queries — though with varying degrees of accuracy — but its biggest shortcoming perhaps is that it cannot access real-time information from the Internet.
• ChatGPT’s language model was trained on a vast dataset to generate text based on the input, and the dataset, at the moment, only includes information until 2021.

Is Bard better than ChatGPT?

• Bard looks like a limited rollout right now.
• Google is looking for a lot of feedback at the moment around Bard, so it is hard to say whether it can answer more questions than ChatGPT.
• Google has also not made clear the amount of knowledge that Bard possesses.
• For instance, with ChatGPT, we know its knowledge is limited to events till 2021.
• Of course, it is based on LaMDA, which has been in the news for a while now.

Why has Google announced Bard right now?

• Bard comes as Microsoft is preparing to announce an integration of ChatGPT into its Bing Search engine.
• Google might have invented the ‘Transformer’ technology, but it is now being seen as a latecomer to the AI revolution.
• ChatGPT in many ways is being called the end of Google Search, given that conversational AI can give long, essay style and sometimes elegant answers to a user’s queries.
• Of course, not all of these are correct, but then AI is capable of correcting itself as well and learning from mistakes.

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As per a new study, researchers are examining the fortress wall of Xi’an, an ancient city in China, by using tiny outer space particles ‘Muon’ that can penetrate hundreds of metres of stone surfaces.

What are Muons?

• Muons are subatomic particles raining from space.
• They are created when the particles in Earth’s atmosphere collide with cosmic rays — clusters of high-energy particles that move through space at just below the speed of light.
• About 10,000 muons reach every square metre of the Earth’s surface a minute.
• These particles resemble electrons but are 207 times as massive.
• Therefore, they are sometimes called “fat electrons”. Because muons are so heavy, they can travel through hundreds of metres of rock or other matter before getting absorbed or decaying into electrons and neutrinos.
• In comparison, electrons can penetrate through only a few centimetres. Muons are highly unstable and exist for just 2.2 microseconds.

What is muon tomography or muography?

• Muography is conceptually similar to X-ray but capable of scanning much larger and wider structures, owing to the penetration power of muons.
• As these high-energy particles are naturally produced and ubiquitous, all one needs to do is place a muon detector underneath, within or near the object of interest.
• The detector then tracks the number of muons going through the object from different directions, to form a three-dimensional image.

Muons and archaeology

• The technique was first used in the late 1960s, when Nobel Laureate and US experimental physicist Luis Alvarez joined hands with Egyptologists to search for hidden chambers in the Pyramid of Khafre, Giza.
• Nothing was found at the time.

Recent feats achieved

• In 2017, modern archaeologists repeated the experiment with more sophisticated and advanced muon detectors and stumbled upon a major finding.
• By placing several detectors, the archaeologists were able to discover a previously unknown chamber at least 30 metres long.
• It was the first major inner structure to be found in the pyramid since the 19th century.

Uses of muography beyond archaeology

• Apart from archaeology, muography has found use in customs security, internal imaging of volcanoes and others.
• Around 2015, scientists used the technique to look inside the Fukushima nuclear reactors after the 2011 earthquake and tsunami in Japan.
• As the site was highly radioactive, they put the two muon detectors in 10 centimetres thick boxes to protect them from radiation and then carried out the scanning.
• Muography is also being used by researchers to analyse Mount Vesuvius, a volcano in Italy.

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